Wrapper classes

[Sudipta Das]

All the wrapper classes (Integer, Boolean, Float, Short, Long, Double and Character)

1.are public
2.are serializable
3.are immutatable
4.extend java.lang.Number
5.are final

[Art Metzer]

/*
 * @(#)Integer.java1.62 00/02/02
 *
 * Copyright 1994-2000 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */
package java.lang;
/**
 * The Integer class wraps a value of the primitive type <code>int</code>
 * in an object. An object of type <code>Integer</code> contains a
 * single field whose type is <code>int</code>.
 * 

 * In addition, this class provides several methods for converting
 * an <code>int</code> to a <code>String</code> and a
 * <code>String</code> to an <code>int</code>, as well as other
 * constants and methods useful when dealing with an
 * <code>int</code>.
 *
 * @author  Lee Boynton
 * @author  Arthur van Hoff
 * @version 1.62, 02/02/00
 * @since   JDK1.0
 */
public final class Integer extends Number implements Comparable {
...
}

[Sudipta Das]

Originally posted by Sudipta Das:
All the wrapper classes (Integer, Boolean, Float, Short, Long, Double and Character)

1.are public
2.are serializable
3.are immutatable
4.extend java.lang.Number
5.are final

I suppose my question was misinterpreted. I meant to ask which is the correct answer of the fol. question :
All the wrapper classes (Integer, Boolean, Float, Short, Long, Double and Character)

1.are public
2.are serializable
3.are immutatable
4.extend java.lang.Number
5.are final

[Thomas Paul]

public final class Character extends Object implements java.io.Serializable
public final class Boolean implements java.io.Serializable
public final class Double extends Number
public final class Float extends Number
public final class Integer extends Number
public final class Long extends Number
public final class Short extends Number
public abstract class Number implements java.io.Serializable
So the answer is:
1, 2, 3, 5

------------------
Moderator of the Programmer Certification Forums

[Thomas Paul]

I never noticed but the Character class specifically extends Object. That's a little odd, isn't it?